assets/demo/qs/javascript/2/2.4-search-getelementsbytagname.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Search getElementsByTagName</title>
</head>
<body>
<button class="getElementsByTagName">getElementsByTagName</button>

<ul>
    <li>1</li>
    <li>2</li>
    <li class="list">3</li>
    <li>4</li>
    <li class="list">5</li>
    <li>6</li>
    <li>7</li>
    <li>8</li>
    <li class="list">9</li>
    <li class="list">10</li>
</ul>

   <script>
       document.querySelector(".getElementsByTagName").addEventListener('click', () => {
           let elements = document.getElementsByTagName('li');
           for (let elem of elements) {
               elem.style.backgroundColor = 'red';
           }
       });
   </script>
</body>
</html>